The inventive concepts relate to semiconductor devices, and more particularly, to semiconductor device having a multi-threshold voltage.
A semiconductor device may include a plurality of metal-oxide semiconductor (MOS) transistors having a plurality of threshold voltages, that is, a multi-threshold voltage, in order to be configured to perform various functions. Manufacturing semiconductor devices having a multi-threshold voltage may include reliably forming a plurality of gate structures having different work functions on a substrate without affecting a manufacturing process.